[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Advice Needed
--- Tom Droege <tdroege2@earthlink.net> wrote:
> Dan and I just went up and awakened TOM2 and TOM3 from their winter
> hibernation in the dome.
>
> I want to install a camera in the dome, and use the RS232 link to
> open and
> close it.
>
> I would like to do all this under linux, but will use Windos and
> QBasice if
> desperate.
>
> Here is what I need to be able to do:
>
> 1) I will put a separate linux machine in the dome. There is none
> there
> now. It will be on the ethrenet.
The other option would be to install a serial <--> ethernet
device in the dome. That and an ethernet camera. One less
PC to deal with. ut if you have the PC it's free.
>
> 2) I want to install a cheap webcam on this machine. I want one that
> will
> just work, otherwise it will be easier to use Windows. Since cameras
> are
> so cheap, I am quite willing to buy one that is known to work. This
> seems
> to be the easiest approach to using something on linux.
They make "ethernet cameras" that don't require a computer.
That would be very easy to do.
I just tried "linux webcam" on google and got plenty of good hits.
It seems webcam drivers have been builtinto the Linux kernel
for some time now. Seems to be a few web pages and e-mails lists
for using web cam under Linux
>
> 3) I want to run a simple program on the linux machine which sends
> characters out on the serial port. Best if I can do this in a perl
> program. I need to be able to send the single characters A, a, B, b
> in
> order to control the two halves of the dome up or down. Really
> complicated
> stuff. It looks like I will need to send about 10 "A"s a spaced in
> time to
> open one half of the dome and 10 "a"s spaced in time to close the
> dome. So
> I need to know a little about time. I need to specify, for example,
> how
> long a "send and 'a' a second" loop is to run. I don't need
> precision
> time. But I do need rough knowledge of time. Hmmm! I guess i can
> just
> read Date and parse it to get what I want. DOS has a seconds since
> midnight, does linux have a similar time command?
UNIX/Linux keeps time as "seconds from epoc".I hate to say
"read the manual.
but look at the man page "man perlfunc" to see what is available.
You will find
Time-related functions
"gmtime", "localtime", "time", "times"
time Returns the number of non-leap seconds since
whatever time the system considers to be the epoch
(that's 00:00:00, January 1, 1904 for Mac OS, and
00:00:00 UTC, January 1, 1970 for most other
systems). Suitable for feeding to "gmtime" and
"localtime".
>
> 4) I want to be able to sit in my office elsewhere on the ethernet
> and open
> a window that shows what the camera sees.
I think the way hese work is you run the Apache web server in
the Linux machine and have the camera write .jpg fileswith a
given name int the servers documents directory. Then you
point your web browser at the Linux web server. On a 100BaseT
network you could do a few frames perseconf that way.
Then I want to open a
> terminal
> and run the program to open and close the dome. I don't trust the
> mechanics of the dome, so I want to be able to watch it when I move
> it. Possibly I will want to run more than one camera at a time to
> see what
> I want to see. One might be outside looking at the weather.
>
> All this sort of thing is known to work on linux, I just have to
> learn to
> do it. So if you all advise me to go ahead, then someone will have
> to lead
> me by the hand.
>
> This is, of course, great fun. Mad scientist at work, and all that.
> We
> were able to test that the RS232 control worked to control the dome
> with a
> QBasic test program.
>
> Tom Droege
I just found out about the "XPORT". It is basically a smaller
cheaper replacement for the Linux computer you would put in the
dome. At $33 and less then an inch cubed.
A complete
web server, computer, software, Ethernet interface and all that is
bultinto an RJ45 shell. It don't get much smaller then that.
Price is $33.00 each. New computers don't get much cheaper.
On one side of the device is the RJ45 jack on the other is a high
speed (300Kbps) serial port. The purpose of the device is to reduce
engineering costs of developing network enabled devices. At this
price and size you could afford to build a web based status display
on a dometic hot water heater or washing machine.
Or it could be used on a Mk-X camera. The camera would be designed
to work with a serial interface. Testing and checkout could be
done using a PC's serial port. Later the designer adds this RJ45
shell. The camera still "thinks" it is a serial device. If you
are willing to write some Java code that lives in the RJ45 shell
then your device can have a web based setup or status page.
I have seen Linux computers built on the SIMM strip form
factor but inside an RJ45 shell beats even that.
http://www.commanderx.com/productinfo.html
=====
Chris Albertson
Home: 310-376-1029 chrisalbertson90278@yahoo.com
Cell: 310-990-7550
Office: 310-336-5189 Christopher.J.Albertson@aero.org
KG6OMK
__________________________________________________
Do you Yahoo!?
Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
http://platinum.yahoo.com